Triangle Area Formula, A= b × h /2, Why?

#####Triangle Area, A= b × h /2, why?

Given any triangle, for a chosen base b and the corresponding height (altitude) h, the area is *b × h /2*. But why? Without knowing the conceptual foundation, we frequently have students struggling to find the base and the corresponding height. Any side can be the base; once that is chosen, the height is fixed.

To see why, two congruent copies of a triangle make a parallelogram, which can be easily converted to a rectangle with the same base (b) a